Belt-tightener.



lessees.

To all 'whom it may concern:

Be it known that l, CHARLES Yonne, a citizen of the United States, residing in the city of Webster Groves, in the county of Saint Louis and State of Missouri, have in-y vented a new and useful Belt-Tightener, of which the following is a specification.

. My invention relates to improvements inl belt tighteners, especially designed 'for use in connection with powersewing machines, wherein a pivotally mounted arm, carrying a sheave arranged to ride'the machine belt, is acted upon by a spring, which `may be varied as to tension by means readily accessible to the machine operator from the top of the machinetable.

The object of my improvements is to construct a spring actuated, belt tightener of simple and inexpensive design which may be readily adapted to either straight or twist belts, in which latter case it serves as a separator to prevent `wear on the belt, and to arrange means, conveniently accessible to the machine operator and vactuatable with a minimum of effort, for varying the spring tension in a'minimum of time, to compensate for varying belt conditions.

My improvements consist in the novel construction, arrangement and combination of parts, hereinafter fully, clearly and concisely set forth in my specification, pointed out inl my claims and illustrated by the accompanyino drawing, in which- 2ligure 1 is an elevation, partly in section, of a belt tightener embodying my improvements, showing in section a fragment of a machine top and fragments of a machine pulley and belt.

Fig. 2 is an end elevation of the bearing for the tightener arm and the spring barrel, and

Fig. 3 is a plan of the complete device, removed from the machine.

Referring to the drawings by numerals, a designates a base-plate, having counter-sunk screw holes 5, whereby it may be secured to the bottom face of the machine table top. Formed integral with the base-plate, dependently, are the relatively spaced, perforated ears 7 for the support of a short shaft 8, and in one of said ears there is formed a hole 9 for a pin 10 in order to hold the short shaft against axial movements.

Projecting laterally and integrally from the base-plate, preferably in the plane nnrfrrrenrnivnn.' Y.

i Specification of Letters Patent.

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web and integraltherewith,is a cylindrical barrel 12, whose trendis at a right angle to the baseplate d and which is internally threaded throiighout its lengthA to ,form-a seat 'for an abutment plug 1??, providedwith an lupstand-ing and non-circularhead lil to facilitate its adjustment.

v-Mounted on the short shaft 8 is a rocker arm 15, bifurcated at its free end toreceive asheave 16, which 1s rotatably mounted l`on,

a shaft 17, and arranged to bear on the belt 18, which drives the machine, through :the

pulley 19, from a power-driven wheel, not.

wheel; the barrel 12 extended upwardly therethrough, and, when the machine is a straight belt drive thebase plate 4 is positioned at a right angle to the trend of the belt and secured by screws, or otherwise, to

the bottom face of the machine top, therebyholding Athe sheave 16 in line with the straight belt.

The arm 15, with the sheave 16, is then pivotally mounted in the ears 7, by means of the short shaft 8 and the spring 21 dropped through the barrel to rest on the cup 20; the abutment plug 13 is then screwed into the barrel a distance to produce the desired spring tension. y

When the machine is a twist belt drive, substantially the same procedure is followed, except for the positioning of the base plate, which is angular to the table top, so that the arm 15 and sheave will parallel the trend 0f the twist belt, and in which instance the sheave serves to hold `the belt at its point of crossing from wearing upon itself.

In useythe desired tension is maintained by a simple rotation of the abutment plug,

l which may be accomplished, when necessary,

by the machine operator and by the employment of a simple socket wrench.

Having thus described my invention, `what ll claim, as new therein and desire to secure by Letters-Patent of the United States, therefor, is

Patented Dec., 3,19%@

Application filed August 25, 191'?.` I Serial No. liIBBJZElO.`

thereof,is a web 11 and supported 1. A belt tightener comprising a sheave, a rocker arm, a pivotal support for the rocker arm, a threaded barrel carried by said support, a spring arranged to act on said rocker arm and means having a threaded connection with said barrel for varying the tension of the spring.

2. In a belt tightener, the combination with a base plate having means for attachment to a machine top, an integral bearing and an integral, internally threaded barrel, a rocker arm, carrying a sheave, mounted on said bearing and having a spring abutment adjacent said bearing, a spring and a screwplug abutment in said barrel.

3. In combination ywith a machine top having a hole formed vertically therethrough, an open-ended, internally threaded barrel extended through said hole, a pivot support havin xed relation with said barrel and arrange to be secured in various angular relationships With the top, a rocker arm carried by said support, a sheave on said arm arranged to ride the belt of the machine, a

spring acting on said rocker arm, and a screw plug in said barrel forming an adjustable abutment for the spring.

4. In a belt tightener, an element arranged to bear on a machine belt, a yielding pressure device acting on said element, means for varying the tension of said pressure device and means for securing the belt tightener, as a Whole, in various positions to a machine, all of said parts bearing a constant assembled relationship.

5. In combination with a machine top having a hole therethrough, a support arranged to be secured beneath the machin@` top, an element arranged to be connected with said support and to ride a driving belt for the machine, and a tension device arranged to bear on said element and having an adjustable part located with relation to said hole as to be susceptible of adjustment, to eiliect a variation of tension on the belt, through said hole and from the upper side of the machine top.

CHARLES B. YODER.

kCopier. of this patent may be obtained for ve cents each, by addressing the Commissioner of Iatents,

l Washington, D. C. 

